Part of the Smithsonian complex but not officially counted as a museum, the S. Dillon Ripley Center is notable for housing Discovery Theater, which stages children’s plays and entertainment (at the Ripley Center, and at other locations on and off the Mall, and at the International Gallery, which hosts rotating exhibits of works from various Smithsonian museums). Look for the copper-domed, hutlike structure next to the Smithsonian Castle. Galleries and the Discovery Theater are actually subterranean and connect underground to the Freer, Sackler, and African Art museums.